1. Field of the Invention
This invention relates to the use of N,N-disubstituted phthalamic acids and/or N,N-disubstituted phthalamic acid ammonium salts, their use as surfactants, emulsifiers and conditioning agents in shampoos.
2. Description of the Related Art
Human hair becomes soiled due to its contact with the surrounding atmosphere and, to a greater extent, from sebum secreted by the head. The build-up of the sebum causes the hair to have a dirty feel and an unattractive appearance. The soiling of the hair necessitates its being shampooed with frequent regularity.
Shampooing the hair cleans by removing excess soil and sebum. However, the shampooing process is disadvantageous because the process results in hair that is left in a wet, tangled and generally unmanageable state. A variety of approaches have been developed to alleviate the after-shampoo problems. These range from the inclusion of hair conditioning aids in shampoos to post-shampoo application of hair conditioners, i.e., hair rinses. Hair rinses typically work by depositing a polymeric film or other material onto the hair. However, the use of such solutions as conditioners has not been fully satisfactory. For one thing, hair rinses are generally liquid in nature and must be applied in a separate step following the shampooing, left on the hair for a length of time, and finally rinsed with fresh water. This, of course, is time consuming and inconvenient. Furthermore, hair rinses or the leave-on hair conditioners, in addition to requiring an extra step, are difficult to apply in just the right amount of product and are not evenly distributed throughout a head of hair.
While shampoos have been disclosed which contain conditioning aids, these shampoos have not been totally satisfactory for a variety of reasons. One reason relates to a lack of compatibility between surfactants which are good cleaning agents and fatty cationic agents which are good conditioning agents. This lack of compatibility caused other surfactants such as nonionics, amphoterics and zwitterionics to be examined by workers in the field. However no satisfactory solutions have been found. Shampoo conditioners must be applied in a separate step after shampooing, left on the hair for a period of time and then rinsed with water. This process is time consuming and inconvenient.
Suspending/emulsifying agents have been used for cationics in shampoo compositions with surfactants and silicone materials. Normally, a suspension system comprising of xanathan gum, glycerol distearate and cetyl alcohol is used. Manufacturing these compositions is extremely complex, costly and time consuming.
U.S. Pat. No. 4,741,855 describes shampoo compositions which comprise a synthetic surfactant, an insoluble, non-volatile silicone, a suspending agent, and water. The described suspending agents include long chain esters of ethylene glycol, esters of long chain fatty amine oxides and many others. There appear to be several key conditioning components in these compositions, including an insoluble, non-volatile silicone, a suspending agent and a quaternary ammonium compound. The quaternary ammonium compounds, disclosed in U.S. Pat. No. 4,741,855 as ingredients in a shampoo composition are di(hydrogenated tallow) dimethyl ammonium chloride and cetyltrimethyl ammonium chloride.
The use of silicone material in shampoos has been described in a number of different publications. The manufacture of such compositions is extremely complicated and requires specialized mixing equipment, high shear pumps, a heat exchanger, several manufacturing tanks, etc.
Quaternary ammonium compounds derived from fatty acid amines such as tallow amine and di-tallow amine have been used as conditioners, surfactants and thickeners or emulsifiers in various shampoo and hair care products. For example, European Patent Application No. 0067635A2 discloses conditioning shampoos containing quaternary ammonium compounds of the formula: ##STR3## wherein the R.sup.1 and R.sup.2 groups contain an average of from about 16 to 22 carbon atoms most preferably from about 16 to about 18 carbon atoms, R.sup.3 and R.sup.4 are C.sub.1 to C.sub.4 alkyl or hydroxyalkyl groups, and X is any compatible anion, particularly one selected from the group consisting of halide, hydroxide, methylsulfate, or acetate anions.
The shampoo compositions of that patent application also contain acyl derivatives which are long chain amides, alkanolamides, esters of ethylene glycol and glycerine, esters of carboxylic acids. esters of thiodicarboxylic acids, and mixtures of these derivatives. The shampoo compositions of that patent application also contain surfactants which are represented by the formula: ##STR4## wherein R.sup.1 is a long chain alkyl radical having from about 10 to about 18 carbon atoms or an amido radical represented by the formula: ##STR5## wherein R.sup.5 is a long chain alkyl radical, R.sup.2 and R.sup.3 are each alkyl radicals having from about 1 to about 3 carbon atoms. R.sup.4 is an alkylene or hydroxy alkylene radical having from about 1 to about 4 carbon atoms and X is a carboxylate radical.
European Patent Application No. 0 152 194 A2 discloses shampoo compositions containing quaternary ammonium salts of the formula:
wherein R.sub.1 is hydrogen, or an aliphatic group of from 1 to 22 carbon atoms, or an aromatic, aryl or alkaryl group having 6 to 20 carbon atoms; R.sub.2 is an aliphatic group having from 12 to 22 carbon atoms; R.sub.3 and R.sub.4 are each alkyl groups having from 1 to 3 carbon atoms; and X is an anion selected from halogen, acetate, phosphate, nitrate and methyl sulfate radicals.
U.K. Patent Application No. GB 2196979 A provides hair care compositions comprising compounds of the formula:
wherein R.sub.1 and R.sub.2 are aliphatic groups containing from about 12 to about 22 carbon atoms, R.sub.3 and R.sub.4 are hydrogen or short chain alkyl groups containing from about 1 to about 4 carbon atoms and X is anion selected from halogen, acetate, phosphate, nitrate and alkyl sulfate radicals.
U.K. Patent Application No. GB 2124647 A teaches quaternary ammonium compounds useful in shampoo compositions. The ammonium compounds have the formula: ##STR6## wherein R.sub.1 is an aliphatic alkyl group containing an average of from about 16 to 22 carbon atoms, most preferably from about 16 to about 18 carbon atoms, the R.sub.2 groups are C.sub.1 to C.sub.4 alkyl or hydroxylalkyl groups, the R.sub.3 groups are alkylene oxide groups, preferably propylene oxide, where y is 1-4 and X is any compatible anion, particularly one selected from the group consisting of halide, hydroxide, methylsulfate, or acetate anions.
European Patent Application No. 0294 894 discloses conditioning agents for delivery from shampoos comprising compounds of the formula: ##STR7## wherein R.sub.1 and R.sub.2 can independently be C.sub.16 to C.sub.20 alkyl or alkenyl and R.sup.3 is H or CH.sub.3, and A is an anionic surfactant selected from the group consisting of alkyl sulfonates, aryl sulfonates, alkylaryl sulfonates, alkyl sulfates, alkyl ethoxylated sulfates, dialkyl sulfosuccinates, ethoxylated alkyl sulfonates, alkyl oxybenzene sulfonates, acyl isethionates, acyl alkyl taurates, olefin sulfonates and paraffin sulfonates.
A wide variety of surface active (surfactant) compounds are known and widely used. Further, certain relatively specific phthalamate derivatives are at least nominally disclosed in academic and patent literature. Some specific phthalamate derivatives have been suggested as being useful in plant growth regulator formulations insect repellent formulations, bactericidal. fungicidal, herbicidal formulations, additives for improving low temperature flow characteristics of petroleum distillate fuels, solvent extraction formulations for certain heavy metal ions, catalyst systems for polyurethane foam formulations, additives for thermal recording materials, thickeners for silicone grease and oil-based drilling muds, additives for water-insensitive coatings, plasticizers, etc. Phthalamic acids or phthalamate derivatives have been used as additives for insecticidal compositions; additives for vulcanization activators; additives for rust and corrosion inhibitor formulations; additives to screen-clogging prevention and rust inhibition formulations; additives for improving low temperative flow characteristics of petroleum fuel oils; additives to catalyst systems for polyurethane foam formulations.
Ammonium phthalamates have been used as additives in fuel oil compositions, blending agents for grease, lubricating oil additives, and thickening agents for lubricating oil compositions. These ammonium phthalamates have the formula ##STR8## wherein
R.sub.1, R.sub.2, R.sub.3 and R.sub.4 are the C.sub.16 -C.sub.40, preferably C.sub.16 -C.sub.24 straight chain alkyl groups of secondary amine, and may be the same or different.
Tallow is a fatty acid byproduct of the meat-packing industry obtained by rendering the body fat from cattle and sheep. Tallows from different sources vary in free fatty acid content. The fatty acids normally found in tallow are myristic acid, palmitic acid, stearic acid, oleic acid, and linoleic acid.
Several methods are known for the preparation of tallow amines, but the most common method in industry is the conversion of a fatty acid to a nitrile by treating with ammonia, followed by catalytic hydrogenation of the nitrile to primary, secondary, or tertiary amine by suitable adjustment in the reaction conditions. Tallow amines as well as di(hydrogenated tallow) amine, are commercially available; for example, di(hydrogenated tallow) amines are available under the trade name ARMEEN 2HT.TM. (Akzo Chemicals, Chicago, Ill.).
Various routes exist for the preparation of phthalamic acids and phthalamic acid salts. In U.S. Pat. No. 4,402,708 N,N-diarachidyl phthalamic acid was prepared by adding phthalic anhydride to a 40% solution of amine in toluene in a 1/1 mole ratio at 80.degree. C. The product was recovered by vacuum drying at 50.degree. C., 0.05 mmHg for 20.5 hours. Phthalic anhydride sublimation was observed. This method makes no mention of the presence of any ammonium salt in the resultant product.
U.S. Pat. No. 4,402,708 describes a method for preparing N,N-dioctadecyl phthalamic acid dioctadecyl ammonium salt and N,N-diarachidyl phthalamic acid diarachidyl ammonium salt. Phthalic anhydride was added to a 10% solution of amine in toluene in an anhydride to amine mole ratio of 1/2. The product was recovered by filtering and film evaporating a 1/1 toluene/n-heptane solution at 55.degree. C., 40 mmHg.
Phthalamic acids have also been prepared by melting phthalic anhydride at 131.degree. C. and subsequent addition of molten secondary amine. The reactants to be added in an equimolar ratio. At the temperature used in this method, 131.degree. C, excessive phthalic anhydride sublimation occurs and increased product degradation is observed. This method makes no mention of the presence of any ammonium salt in the resultant product.
Phthalamic acids have been prepared by addition of a solution of secondary amine in isopropanol at 78.degree. C. to a phthalic anhydride/isopropanol slurry at 78.degree. C. in a one to one phthalic anhydride/amine molar ratio with subsequent vacuum stripping of the solvent. This method utilizes isopropanol as the solvent for the reaction. Isopropanol, a secondary amine, reacts with phthalic anhydride to yield isopropyl mono ester of phthalic acid. At 78.degree. C., as much as 40% of the product may be this ester.
Each of these methods produces a mixture of the desired phthalamic acid and an ammonium phthalamate salt. However, these methods make no mention of the presence of any ammonium salt in the resultant product.